The present invention relates to a display unit installing and connecting device, and more particularly to a structure which is so constructed that a flexible base plate which is a flexible printed circuit board is folded at the outside of a holding member and urged by means of spring bodies thereby to electrically connect a print board and the flexible base plate, with no need of preparing a connecting terminal formed on the flexible printed circuit board and a connector to be connected thereto.
Conventionally, a display unit installing and connecting device such as the one disclosed in the Unexamined Japanese Patent Application Publication No. Hei 9-288278, for example, has been known. As shown in FIGS. 4 and 5, the conventional display unit installing and connecting device is of such a construction that a back light 3 which serves as a light conductor for conducting lights from a light emitting element 5 to illuminate a liquid crystal display unit 1 from backward is arranged in the rear of the liquid crystal display unit 1, and a flexible base plate 2 connected to the liquid crystal display unit 1 by means of a conductive adhesive 7 is folded in an approximately C-shape, and fixed by means of interposing members 6, and a connecting terminal 8 formed on the flexible base plate 2 is guided to the rear and outward of the back light 3 and connected there with a connecting member such as a connector which is not shown.
As described, in the structure of the conventional display unit installing and connecting device, the back light 3 and the flexible base plate 2 are fixed by means of the interposing member 6. There has been a problem that this fixing operation requires manual labor, which results in an increase of the cost. Moreover, the connecting terminal 8 formed on the flexible base plate 2 is guided outward and connected there to the connector or the like. This incurs another problem of fitting and connecting operation that the connecting terminal 8 and the connector to be connected thereto must be additionally prepared.
With a view to overcoming the above described problems, it is an object of the present invention to provide a display unit installing and connecting device which is inexpensive and reliable in connection, and so constructed that the liquid crystal display unit, the light conductive plate and the flexible base plate can be held by means of a holding member having positioning bosses and engaging claws, that the holding member and a main print board (or printed circuit board) are connected by means of the engaging claws, and that the flexible base plate and the main print board are connected by means of spring bodies provided on the print board.
In order to solve the above described problem, a display unit installing and connecting device according to the present invention comprises a liquid crystal display unit, a flexible base plate which is a flexible printed circuit board connected to the liquid crystal display unit, a holding member for holding the liquid crystal display unit, a print board (or printed circuit board) to which the holding member is fitted, and spring bodies mounted on the print board and having a plurality of conductive springs molded with resin, the flexible base plate being folded at the outside of the holding member, characterized in that the device is further provided with means for electrically connecting the print board to the flexible base plate by means of spring force of the spring bodies.
The invention according to a second aspect of the present invention is embodied in a connecting device comprising a display unit, a flexible base plate connected to the display unit and formed with contact portions on its one face, a holding member for holding the flexible base plate or the display unit, a print board arranged facing with the flexible base plate, and springs provided between the print board and the flexible base plate to electrically connect both of them, characterized in that the flexible base plate is adapted to contact the holding member while urged by means of the springs.
This device has an effect that the print board and the flexible base plate are electrically connected to each other by the spring force by means of the spring body.
The invention according to a third aspect is embodied in a connecting device comprising a liquid crystal display unit including a pair of base plates having a transparent electrode at their inner faces and enclosing therein a liquid crystal composition, a holding member having positioning bosses erected on its rear face and engaging claws in its bottom part which are engageable with the print board, and a flexible base plate electrically communicating with the liquid crystal display unit and folded in an approximately C-shape at its forward end which is provided with positioning holes and contact portions adapted to be electrically connected to below-mentioned springs,
characterized in that the print board is provided with positioning holes, a plurality of conductive springs and light emitting elements,
and that the liquid crystal display unit is held by the holding member with the positioning bosses inserted through the positioning holes in the print board, and with the engaging claws engaged at determined positions of the print board, whereby forced portions of the springs and the contact portions provided on the flexible base plate are fitted and connected to each other.
This structure has an effect that the forced portions of the spring bodies and the contact portions provided on the flexible base plate can be precisely fitted and connected to each other.
The invention according to a fourth aspect is embodied in a connecting device as claimed in any one of the first through third aspects wherein the flexible base plate is provided with the contact portions on its one face along opposite edges which are substantially perpendicular to the folded forward end, and the springs are provided at positions corresponding to the contact portions.
This structure has an effect that the forced portions of the spring bodies and the contact portions provided on the flexible base plate can be precisely fitted and connected to each other.
The invention according to a fifth aspect is embodied in a connecting device as claimed in the first through third aspects, wherein the contact portions formed in the flexible base plate are arranged so as to be substantially symmetrical with respect to a center thereof.
This structure has an effect that the forced portions of the spring bodies and the contact portions provided on the flexible base plate can be precisely fitted and connected to each other with a good balance.
The invention according to a sixth aspect is embodied in a connecting device as claimed in the third aspect, wherein the light emitting elements are adapted to be encased in the holding member, and after they have been encased, radiant lights projected from the light emitting elements are conducted to the light conductive plate by means of a reflecting face provided on the holding member.
This structure has an effect that the radiant light from the light emitting elements are conducted to the light conductive plate by means of the reflecting face provided on the holding member.
The invention according to a seventh aspect is embodied in a connecting device as claimed in the third aspect, wherein the light emitting elements provided on the print board are located further in front of the folded forward end of the flexible base plate.
With this arrangement, the radiant light from the light emitting elements are conducted to the light conductive plate by means of the reflecting face provided on the holding member.
The invention according to a ninth aspect is embodied in a connecting device as claimed in any one of the first through third aspects, wherein each of the springs is formed of a metal piece folded to have a spring characteristic.
This feature has an effect that the metal pieces of the conductive springs are bent to have a spring characteristic.
The invention according to a tenth aspect is embodied in a connecting device as claimed in any one of the first through third aspects, wherein each of the springs includes a plane parallel to the print board on which they are mounted.
This feature has an effect that a plurality of the conductive springs can be mounted in parallel to the print board.
The invention according to an eleventh aspect is embodied in a connecting device as claimed in any one of the first through third aspects, wherein each of the springs is bent and its distal end is directed downward.
Because each of the conductive springs are bent and the distal end is directed downward, a sufficient spring characteristic can be assured.
The invention according to a twelfth aspect is embodied in a connecting device as claimed in any one of the first through third aspects, wherein the springs mounting area of the print board on which the springs are mounted, and the contact portions of the flexible base plate are provided with the same kind of metal coatings.
This feature has an effect that contact resistance will be reduced and potential difference of the contact portions can be eliminated.
The invention according to a fourteenth aspect 14 is embodied in a display unit installing and connecting device as claimed in the second or third aspects, wherein a plurality of the conductive springs are all formed of the same metal pieces.
Because of the same metal pieces, a plurality of the conductive springs can be easily manufactured.